Expansible linkage with abutment pivot points



July 24, 1956 G. IHRINGER 3 5 EXPANSIBLE LINKAGE WITH ABUTMENT PIVOT POINTS Filed July 15. 1953 RHARD mama &'

United fitates 2,755,617 Patented July 24, 1956 EXPANSIBLE LINKAGE WITH ABU'INENT PIVOT POINTS Gerhard Ihring'er, Pfor'zlieim, Germany, assignor to Rodi & Wienenberger Aktiengesellschaft, Pfornheim, Germany, a firm Application July 13, 1953, Serial No. 367,694 Claims priority, application Germany June 20, 1953 6 Claims. (Cl. 59-49) The present invention relates to an elastic one-legged link-band of the scissor-like opening or stretching kind, that is to say, of a link-band which has its links rotatably coupled to each other alternately at one end and thereupon at the opposite end of the links.

Link-bands of this kind, consisting of intersecting links which are pivotally connected to each other and stretching against spring resistance after the fashion of Nuremberg scissors or lazy tongs, have already been known to the art. However, the stretchability of link-bands of this known type exceeds considerably the stretchability of draw-link-bands, and that is why they are unsuited for watch-bands which are not provided with locking means, but have to be slipped over the hand of the wearer in stretched condition.- In addition to that, the manufacture of these known link-bands is comparatively complicated and expensive, because of the many joints which have to be produced in a cumbersome way through riveting.

In order to reduce the number of the joints, it has already been tried to construct one-legged scissor-like opening link-bands consisting of upper and lower links which are pivotally secured to each other at their ends. But here again the joints had to be produced through riveting, and the contraction of the link-band was obtained by means of torsion springs.

Contrary to this the assembly of the one-legged scissorlike opening link-band of the invention is effected in the simplest manner without any riveting or soldering, and, in additon to that, the novel link-band consists of a comparati'vely very small number of individual parts (only 3 or 4).

This is obtained by the feature that the box-like links are coupled to each other by means of uniformly shaped coupling members in such a way that into every link end one coupling member extends from an adjacent link, and that the two coupling members which thus extend from adjacent links into every link are, in cooperation with spring-means provided in the links, rotatably supported in the links with respect to the longitudinal axis of the links, whereby the construction is so devised that between the coupling means and spring means, on the one hand, and the box-like links, on the other hand, no rigid connection exists.

A link-band of the aforedescribed kind may be provided either with compressing springs or torsion springs, and the parts required are merely: casing with bottom, coupling member, spring.

If torsion springs are employed, these torsion springs have one of their arms fastened against displacement in the coupling members, while the other arm bears against the wall of the casing. In the latter case, two torsion springs are needed for every casing. As already mentioned, the coupling members are not rigidly connected to the casings, and are maintained in position merely by the pressure of the springs.

The coupling members employed in association with torsion springs consist of elongated sheet metal strips provided with holes for the reception of the coiled portionsof the springs, with additional holes for the anchoring therein of one of the spring ends, and possibly also with slots for the engagement therein of portions of the casing for the purpose of guidance of the links.

The casings are preferably of box-like shape and provided with lateral slots through which the coupling members extend from one link into the adjacent link.

Additional features and advantages of the invention will be understood from consideration of the following detailed description taken in connection with the accompanying drawings, forming a part of this specification, and in which two embodiments of the invention have been shown by way of illustration. However, I wish to say that the invention is not confined to any strict conformity with the showing of the drawings, but may be changed or modified, so long as such changes or modifications mark no material departure from the salient features of the invention as expressed in the appended claims.

In the drawings:

Figs. 1 to 3 are, respectively, a side view, a top view, and a cross-sectional View of the bottom of a box-link;

Figs. 4 and 5 are, respectively, a top view, and a longitudinal section of the appertaining box-link;

Figs. 6 and 7 are, respectively, a top view, and a longitudinal section on line VII-VII of Fig. 6, of a coupling member employed in combination with torsion springs;

Fig. 8 is a bottom view of a form of construction provided with torsion springs, two of the bottom parts having been removed to show the interior the links;

Fig. 9 is a sectional view on line IX-IX of Fig. 8;

Fig. 10 is a view of the construction of Fig. 8 in outstretched condition.

Referring now to the drawings in detail, the box-like casing of the box-links consists of the cover part 2 and bottom part 3. Both parts can in simple manner be secured to each other through pressing of the flap-like portions 4 into the recesses 5 and 6.

The coupling members 8 are shaped as illustrated in Fig. 6. In the holes 20 and 21 of the coupling members 8 the coiled portions of the torsion springs 22 are so arranged that the two end portions 23 and 24 of the springs are positioned on different sides of the coupling members. At their free end the spring portions 23 are provided with a bent-off portion, which is pushed into the holes 25 and thus secures the spring portions 23 in their position at the coupling members 8. After both of the springs 22 have been loosely attached to the coupling members 8 in the aforedescribed manner, the coupling members are arranged in the box-like casings in such a way that the portions 24 of the springs bear against the wall of the casings, whereby the coupling members 8 extend through the lateral slots 9 of the casings, and whereby the projecting tongues 27 of the casing are guided in the slots 26 of the coupling members 8. As fulcrum for the coupling members 8 during the stretching of the link-band serves the pointed end 28 of the coupling members 8.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An elastic one-legged link-band of the scissor-like opening and expanding type comprising a plurality of elongated box-like links in parallel position with regard to each other, each of said links being provided with lateral slots in opposite side walls; a plurality of elongated coupling members each having two end portions; each of said coupling members being mounted through the slots in the side walls of a first and second link adjacent one another in said link-band, with one end portion in said first link near the one end thereof, and with its other end portion in said second link near the end of said second link opposite said one end of said first link; each of said coupling members having abutments adjacent the ends and on opposite sides thereof which abut against the adjacent side wall of the links in which the coupling member is mounted, said abutments acting as pivot points during the expansion and contraction of said link-band; means limiting pivotal action of said coupling members and spring means mounted on each end portion of said coupling members said spring means being fastened with its one end to said coupling member and bearing with its other end against said elongated side wall next to said lateral slot, so as to hold said end portion of said coupling member rotatably without the use of pivot means inside said end of said link while urging said coupling member in the direction toward the interior of said link.

2. An elastic one-legged link-band of the scissor-like opening and expanding type comprising a plurality of elongated box-like links in parallel position with regard to each other, each of said links being provided with lateral slots in opposite side walls; a plurality of elongated flat coupling members each having two end portions and two longitudinal sides; each of said flat coupling members being mounted through the slots in the side walls of a first and second link adjacent one another in said link-band with one end portion in said first link near the one end thereof, and with its other end portion in said second link near the end of said second link opposite said one end of said first link; each of said coupling members having abutments adjacent the ends and on opposite sides thereof which abut against the adjacent side wall of the links in which the coupling member is mounted, said abutments acting as pivot points during the expansion and contraction of said link-band; means limiting pivotal action of said coupling members and spring means mounted on each of said end portions of said flat coupling members said spring means being fastened with its one end to said flat coupling member and bearing with its other end against said elongated side wall next to said lateral slot, so as to hold said end portion of said flat coupling member rotatably without the use of pivot means inside said end of said link while urging said flat coupling member in the direction toward the interior of said link.

3. An elastic one-legged link-band of the scissor-like opening and expanding type comprising a plurality of elongated box-like links in parallel position with regard to each other; each of said links being provided with lateral slots in opposite side walls; a tongue being provided in each of said opposite side walls near opposite ends of said links, said tongue projecting into said lateral slot; a plurality of elongated fiat coupling members each having two end portions and two longitudinal sides; each of said flat coupling members being mounted through the slots in the side walls of a first and second link adjacent one another in said link-band with one end portion in said first link near the one end thereof, and with its other end portion in said second link near the end of said second link opposite said one end of said first link; guiding slots being provided in said flat coupling members near their end portions for receiving therein said projections in said link slots; each of said coupling members having abutments adjacent the ends and on opposite sides thereof which abut against the adjacent side wall of the link in which the coupling member is mounted, said abutments acting as pivot points during the expansion and contraction of said link-band; means limiting pivotal action of said coupling members; and spring means mounted on each of said end portions of said flat coupling members, said spring means being fastened with its one end to said flat coupling member and bearing with its other end against said elongated side wall next to said lateral slot, so as to hold said end portion of said flat coupling member rotatably without the use of pivot means inside said end of said link while urging said flat coupling member in the direction toward the interior of said link.

4. An elastic one-legged link-band of the scissor-like opening and expanding type comprising a plurality of elongated box-like links in parallel position with regard to each other; each of said links being provided with lateral slots in opposite side walls; a tongue being provided in each of said opposite side walls near opposite ends of said links, said tongue projecting into said lateral slot; a plurality of elongated flat coupling members each having two end portions and two longitudinal sides; each of said flat coupling members being mounted through the slots in the side walls of a first and second link adjacent one another in said link-band with one end portion in said first link near the one end thereof, and with its other end portion in said second link near the end of said second link opposite said one end of said first link; and spring means mounted on each of said end portions of said flat coupling member, said spring means being fastened with its one end to said flat coupling member and bearing with its other end against said elongated side wall next to said lateral slot, so as to hold said end portion of said flat coupling member rotatably without the use of pivot means inside said end of said link while urging said flat coupling member in the direction toward the interior of said link; means limiting pivotal action of said coupling member guiding slots being provided in said fiat coupling members near its end portions for receiving therein said projections in said link slots, and thereby guiding said flat coupling member in said link during rotation when said link-band is being expanded, and angular abutments at said end portion of said flat coupling member on opposite sides thereof for limiting the rotary movement of said coupling member away from said link during the expansion of said link band; said abutments abutting against the adjacent side wall of the links in which said coupling member is mounted, thereby acting as pivot points during the expansion and contraction of said link-band.

5. An elastic one-legged link-band of the scissor-like opening and expanding type comprising a plurality of elongated box-like links in parallel position with regard to each other, each of said links being provided with lateral slots in opposite side walls; a plurality of elongated coupling members each having two end portions and being mounted through the slots in the side walls of a first and second link adjacent one another in said link-band, with one end portion in said first link near the one end thereof and with its other end portion in said second link near the end of said second link opposite said one end of said first link; each of said coupling members having abutments adjacent the ends and on opposite sides thereof which abut against the adjacent side wall of the link in which the coupling member is mounted, said abutments acting as pivot points during the expansion and contraction of said link-band; means limiting pivotal action of said coupling members; and resilient spring means associated with each of said coupling members and adapted for urging said coupling members into said parallel position with regard to each other, thereby contracting said link-band.

6. In an elastic one-legged link-band of the scissorlike opening and expanding type comprising a plurality of elongated box-like links in parallel position with regard to each other, each of which links is provided with lateral slots in opposite side walls; the improvement of a plurality of elongated coupling members each having two end portions and being mounted through the slots in the side walls of a first and second link adjacent one another in said link-band, with one end portion in said first link near the one end thereof and with its other end portion in said second link near the end of said second link opposite said one end of said first link; each of said coupling members having abutments adjacent the ends and on opposite sides thereof which abut against the adjacent side wall of the link in which the coupling member is mounted, said abutments acting as pivot points during the expansion and contraction of said link-band; means limiting pivotal action of said coupling members; and resilient spring means associated with each of said coupling members and adapted for urging said coupling members into said parallel position with regard to each 2,371,765 other, thereby contracting said link-band. 2,388,554

References Cited in the file of this patent UNITED STATES PATENTS 5 728,741 Mason May 19, 1903 781,969 Sommer Feb. 7, 1905 6 Levine Mar. 20, 1945 Kreisler Nov. 6, 1945 FOREIGN PATENTS Great Britain Apr. 1, 1908 France May 7, 1915 

